TW202246394A - Apparatus for mixing resin composition for manufacturing polishing pad and method for manufacturing polishing pad - Google Patents

Abstract

The present disclosure relates to an apparatus for mixing a resin composition for manufacturing a polishing pad including: a raw material mixer preparing a mixed raw material including a prepolymer and a foaming agent; a filter connected to the raw material mixer for filtering the mixed raw material; and a pad composition mixer connected to the filter to prepare a curable mixture including the mixed raw material after being filtered and a curing agent, wherein the raw material mixer includes a plurality of rotators having different rotation speeds.

Description

Resin composition mixing device for preparing polishing pad and polishing pad preparation method

The present embodiment relates to a resin composition mixing device for preparing a polishing pad, a method for preparing a polishing pad, and the like.

The Chemical Mechanical Polishing (CMP) process is a process for chemically and mechanically planarizing the concave-convex portion of a polished object such as a wafer surface. In the case of a wafer, the surface of the wafer is chemically reacted by supplying a slurry in a state where a polishing object is attached to a polishing head and in contact with the surface of a polishing pad formed on a platen to In many cases, planarization is performed by relatively moving the stage and the polishing head.

The polishing layer contained in the polishing pad is one of the essential raw materials that plays an important role in the chemical mechanical planarization process.

The polishing efficiency of the chemical mechanical polishing process and the quality of the polished object after polishing are greatly affected by the chemical mechanical polishing equipment, the composition of the slurry composition, and the shape and physical properties of the polishing pad.

Polishing pads are usually made of polyurethane. For example, polyurethane formed by mixing a prepolymer, a foaming agent, a curing agent, etc., putting the mixture in a mold and performing a curing reaction is prepared, and the polyurethane is processed so that a polishing pad can be made.

prior art literature patent documents Patent Document 1 Korean Granted Patent No. 10-0467765 (2005.01.13.) Patent Document 2 Korean Granted Patent No. 10-1894071 (2018.08.31.)

technical problem

Embodiments provide a technique capable of efficiently mixing raw materials for preparing a polishing pad and capable of removing metallic foreign matter contained in the raw materials during the mixing of the raw materials.

solution to the problem

A resin composition mixing device for preparing a polishing pad according to one embodiment includes: a raw material mixing part for preparing a mixed raw material including a prepolymer and a foaming agent; a filter unit connected to the above-mentioned raw material mixing part for the mixing The raw material is filtered; and the mat composition forming part is connected with the above-mentioned filtering unit to prepare a curable mixture including the filtered mixed raw material and a curing agent.

The above-mentioned raw material mixing unit may include a plurality of rotating tools having different rotational speeds from each other.

The filter unit may include a second filter unit for separating metal substances from the mixed raw material.

The filtering unit may include: a first filter part for filtering the mixed raw material according to size; and a second filter part for separating metal substances from the mixed raw material.

The first filter unit may include: a filter case through which the mixed raw material moves; and a filter member provided in the filter case through which the mixed raw material passes.

The said filter member passes the said mixed raw material of a predetermined size or less.

The second filter part may include: a filter case through which the mixed raw material passes; a holder provided in the filter case and in contact with the passed mixed raw material; and a magnet provided inside the holder to generate magnetic force.

The metal substance is attached to the outer periphery of the stent by the magnetic force, and is removed from the mixed raw material.

A filter space where the bracket is located is provided inside the filter housing.

An inlet for the mixed raw material to flow into the filter space is provided on the outer periphery of the lower side of the filter housing, which may be arranged along the connection direction of the outer periphery.

An outlet for discharging the mixed raw material passing through the filter space and separating the metal substance is provided on the outer periphery of the upper side of the filter case.

The above-mentioned outlet can be arranged parallel to the above-mentioned wiring direction.

The inlet and the outlet may be diagonally opposed to each other across the bracket.

The second filter part may further include a cover detachably coupled to the filter housing and connected to the bracket.

The raw material mixing unit may include: a raw material mixing container provided with a raw material mixing space; and a raw material mixing tool provided in the raw material mixing space and moved by the plurality of rotating tools.

The above-mentioned raw material mixing tool is used for mixing the above-mentioned prepolymer and the above-mentioned foaming agent accommodated in the above-mentioned raw material mixing space, and dispersing the above-mentioned foaming agent in the above-mentioned mixed raw material.

The aforementioned plurality of rotary tools may include a first drive member and at least one second drive member.

The raw material mixing tool may include: a rotating main body rotatable by being connected to the first driving member, and provided with the at least one second driving member; and at least one raw material mixing member connected to the at least one second driving member. able to rotate.

The at least one raw material mixing member may be rotated by the at least one second driving member.

The raw material mixing member may include: a shaft connected to the driving shaft of the second driving member; and a stirring blade connected to the shaft and accommodated in the raw material mixing space.

The aforementioned stirring blade may include a spiral type stirring blade.

The pad composition forming part may include: a composition mixing container provided with a composition mixing space; and a composition mixing member provided in the composition mixing container.

The above-mentioned composition mixing member prepares a curable mixture by mixing the above-mentioned mixing raw material and the above-mentioned curing agent. The above-mentioned mixed raw material may be a mixed raw material that is filtered while passing through a filtration unit.

The composition mixing member may include: a motor; a shaft connected to the driving shaft of the motor; and a stirring blade connected to the shaft to mix the above-mentioned mixing raw material and the above-mentioned curing agent contained in the above-mentioned composition mixing space.

The above-mentioned resin composition mixing device for preparing a polishing pad may further include a homogenization section for increasing the degree of dispersion of the above-mentioned mixed raw material discharged from the above-mentioned raw material mixing section.

The homogenization unit may include: a homogenization case having an inlet and a discharge port; a rotor rotatably provided inside the homogenization case; and a motor connected to the homogenization case to rotate the rotor.

The homogenization part may include: a homogenization case having an inlet and a discharge port; a shaft rotatably provided inside the homogenization case; and a homogenization plate arranged along the length direction of the shaft and forming a flow hole .

The flow holes of adjacent homogenization plates can be staggered.

A resin composition mixing device for preparing a polishing pad according to another embodiment includes: a raw material mixing part for preparing a mixed raw material including a prepolymer and a foaming agent; a filter unit connected to the above-mentioned raw material mixing part for the above-mentioned The mixed raw material is filtered; and a mat composition forming part is connected with the above-mentioned filtering unit to prepare a curable mixture including the filtered mixed raw material and a curing agent.

The raw material mixing part may include: a raw material mixing container forming a raw material mixing space; a shaft connected to a driving shaft of the driving part and located in the raw material mixing space; and a stirring blade connected to the shaft to rotate.

The stirring blade may mix the prepolymer and the foaming agent supplied to the raw material mixing space while rotating, and disperse the foaming agent in the mixed raw material.

The above-mentioned filter unit may include a second filter part for separating metal substances.

The filter unit may include: a first filter part for filtering the mixed raw material according to size; and a second filter part for separating metal substances from the mixed raw material.

A preparation method of a polishing pad according to another embodiment includes the following steps: a filtering step of filtering a mixed raw material comprising a prepolymer and a foaming agent to prepare a filtered mixed raw material; After the curable mixture of mixed raw materials and curing agent, and the molding step, the above curable mixture is put into a mold and a molded body is prepared; through the preparation method of the above-mentioned polishing pad, at least a part of the molded body is prepared as a polishing pad of a polishing layer .

The above-mentioned filtration includes a filtration process using a magnetic filter.

The above-mentioned foaming agent may include a solid foaming agent, and the above-mentioned solid foaming agent may be a fractionated and purified solid foaming agent.

The effect of the invention

According to an embodiment, the mixing and dispersing process of the resin composition for preparing the polishing pad is controlled by a mixing device for the resin composition for preparing the polishing pad, thereby preparing a curable mixture that is substantially homogeneous and in which the incorporation of foreign matter is controlled, and the mixture is used A polishing pad is prepared, so that the deterioration of the physical properties of the polishing pad caused by the poor curable mixture can be improved, and the polishing quality of the polished object (eg, wafer, etc.) polished by the polishing pad can be further improved.

Hereinafter, multiple embodiments will be described in detail with reference to the accompanying drawings, so that those skilled in the art to which the present invention pertains can easily implement the embodiments. However, the present invention can be realized in various embodiments and is not limited to the examples described in this specification. Throughout the specification, the same reference numerals are given to the same or similar elements.

Throughout the documents of this specification, the terms "about" or "substantially" etc. of degree mean to have the meaning close to the specified numerical value or range with allowable error, and are intended to prevent people from understanding the exact meaning disclosed in the present embodiment. The absolute or absolute values are used improperly or illegally by any unreasonable third party.

Throughout this specification, the term "combination of ..." included in a Markush-type description refers to a mixture or combination of one or more constituent elements selected from the group consisting of constituent elements of a Markush-type description such that It means that the present invention includes one or more constituent elements selected from the group consisting of the above constituent elements.

Throughout the present specification, description in the form of "A and/or B" means "A or B, or A and B".

Throughout this specification, terms such as "first", "second" or "A", "B", etc. are used to distinguish the same terms from each other unless otherwise specified.

In this specification, the meaning that B is located on A means that B is located on A or that B is located on A or can be located on A when there are other layers in between, and it should not be limited to the meaning that B is located on the surface of A in a contact manner. to explain.

Unless otherwise specified, expressions in the singular in this specification are interpreted to include the meanings of the singular or the plural interpreted in the context.

In this specification, in order to explain the present invention, the size of each element in the drawings may be exaggerated and may be different from the actual ratio.

The polishing pad includes a polishing layer in the form of a foamed body that includes cells and has elasticity. A foaming agent and a resin composition are used in the preparation of the polishing layer.

In order to control the particle size of the pores more precisely, a powder-type solid foaming agent (solid foaming agent) is suitable. It is not easy to completely and uniformly disperse powder type blowing agent in liquid polymer resin. When the liquid polymer resin has a viscosity above a certain level, its dispersion is more difficult.

The present inventors have found that at least a part of the solid foaming agent aggregates with each other and easily exists in the mixed raw material in the form of aggregates. Larger aggregates become foreign objects in the polishing pad or change the flow direction of the slurry during polishing. Influence, which not only affects the quality of the polishing pad, but also affects the polishing quality of the polished object.

The present inventors have found that impurities that are unintentionally mixed in the process of preparing the polishing pad have a great influence on the quality of the object to be polished, and metal foreign matter as one of its examples is one of the causes of scratches and the like on the object to be polished one.

Accordingly, the present inventors studied methods of efficiently preparing a polishing pad and methods of improving physical properties of the prepared polishing pad and an object to be polished polished with the polishing pad, thereby proposing embodiments to be described below.

Resin composition mixing apparatus for preparing polishing pads

A resin composition mixing device for preparing a polishing pad according to an embodiment will be explained with reference to FIGS. 1 to 5 .

1 is a schematic diagram showing a resin composition mixing device for preparing a polishing pad according to one embodiment, FIG. 2 is an enlarged view showing a raw material mixing part in FIG. 1 , and FIG. A schematic diagram of a filter part, FIG. 4 is a schematic diagram showing a second filter part in FIG. 1 , and FIG. 5 is an exploded view of FIG. 4 .

Referring to FIGS. 1 to 5, a resin composition mixing device 1 for preparing a polishing pad according to an embodiment includes: a raw material mixing part 10 for preparing a mixed raw material including a prepolymer and a foaming agent; a filter unit 20, and The raw material mixing part 10 is connected to filter the mixed raw material; and the mat composition forming part 50 is connected to the filtering unit 20 to prepare a curable mixture including the filtered mixed raw material and a curing agent.

A resin composition mixing device for preparing a polishing pad according to another embodiment has most of the components of the embodiment described with reference to FIGS. 1 to 7 to be described below.

The raw material mixing part 10 of the embodiment includes at least one driving part (not shown in the figure), and the driving part includes at least one motor.

The driving part is connected to a shaft (not shown in the figure) and rotates, and the stirring blade (not shown in the figure) is rotated inside the raw material mixing container 11 through the shaft, and the supplied prepolymer and the blowing agent are mixed to prepare the mixed raw material.

When the mixed raw material passes through the homogenization part 60 , 70 , the particles are homogenized, and when passing through the filter unit 20 , it is possible to maintain a predetermined size and separate metal substances.

Raw material mixing section: batch type

The raw material mixing part 10 includes: a raw material mixing container 11, which is provided with a raw material mixing space 111 inside; a raw material mixing tool 13, which is arranged in the raw material mixing space 111, and is moved by a plurality of rotating tools 12; and a plurality of rotating tools 12, which make the raw material The mixing tools 13 are operated with different rotational speeds.

The raw material mixing container 11 may be connected to a first supply part 10a for supplying a prepolymer and a second supply part 10b for supplying a blowing agent. In the raw material mixing space 111 of the raw material mixing container 11, the prepolymer and the foaming agent respectively supplied from the first supply part 10a and the second supply part 10b can be accommodated.

A pump (not shown in the figure) for pressure-feeding a mixed raw material prepared by mixing a prepolymer and a foaming agent may be provided in the raw material mixing space 111 . A blower for pressure-feeding a mixed raw material prepared by mixing a prepolymer and a foaming agent may be provided in the raw material mixing space 111 . Pumps and blowers can be selectively applied according to the state of the mixed raw material (solution or powder).

A prepolymer (prepolymer) refers to a polymer resin having a lower molecular weight than a final molded product in which the degree of polymerization is kept at an intermediate stage when preparing a final molded product. Prepolymers can be molded by themselves or reacted with other polymerizable compounds, usually in liquid form.

The above-mentioned liquid prepolymer may include one selected from the group consisting of polyurethane, polyether, polyether, nylon, polyether, polyester, polystyrene, polyolefin, epoxy resin, silicone, and combinations thereof, and It may be a polyurethane-forming prepolymer.

The aforementioned prepolymer may be a prepolymer obtained by reacting an isocyanate compound and a polyol. Illustratively, isocyanate-based compounds, polyols, prepolymers prepared from the above-mentioned isocyanates and the above-mentioned polyols, and the like can be applied.

For example, the isocyanate compounds that can be used to prepare polyurethane prepolymers can be selected from toluene diisocyanate (toluene diisocyanate, TDI), naphthalene-1,5-diisocyanate (naphthalene-1,5-diisocyanate), p-phenylene diisocyanate (p-phenylene diisocyanate), tolidine diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate At least one isocyanate selected from dicyclohexylmethane diisocyanate (dicyclohexylmethane diisocyanate) and isophorone diisocyanate (isophorone diisocyanate).

For example, the polyols that can be used to prepare polyurethane prepolymers can be selected from polyether polyols (polyether polyols), polyester polyols (polyester polyols), polycarbonate polyols (polycarbonate polyols) and acrylic polyols ( at least one polyol from the group consisting of acryl polyol). The polyol may have a weight average molecular weight (Mw) of 300 g/mol to 3000 g/mol.

The polyurethane-based prepolymer may be a polymer having a weight average molecular weight of 500 g/mol to 3000 g/mol, which is polymerized using toluene diisocyanate as an isocyanate compound and polytetramethylene ether glycol as a polyol.

The molded body or the polishing layer as the final molded product may be a foam body having pores (pores).

Pores exist in the molded polyurethane resin in a dispersed manner. The pores may be formed by thermally expandable microcapsules as a solid blowing agent, or may be formed by gas bubbles by applying an inert gas.

Blowing agents include solid blowing agents. The solid blowing agent may be thermally expanded (size-adjusted) microcapsules, and may be a microsphere structure with an average particle diameter of 5 μm to 200 μm. Heat-expandable (size-adjusted) microcapsules can be obtained by heating and expanding heat-expandable microcapsules.

The thermally expandable microcapsules may have a density of 100 kg/m3 or less, or a density of 80 kg/m3 or less. In addition, the above-mentioned heat-expandable microcapsules may have a density of 10 kg/m3 to 80 kg/m3, or a density of 10 kg/m3 to 60 kg/m3.

The heat-expandable microcapsule may include an outer skin containing a thermoplastic resin and a foaming agent encapsulated inside the outer skin. The thermoplastic resin may be one or more selected from vinylidene chloride-based copolymers, acrylonitrile-based copolymers, methacrylonitrile-based copolymers, and acrylic copolymers. In addition, the aforementioned blowing agent encapsulated inside may be one or more species selected from the group consisting of hydrocarbons having 1 to 7 carbon atoms.

The blowing agent encapsulated inside the heat-expandable microcapsule can be selected from such as ethane (ethane), ethylene (ethylene), propane (propane), propylene (propene), nbutane (nbutane), isobutane (isobutene), Butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, petroleum ether (petroleum ether) and other low molecular weight hydrocarbons, such as trichlorofluoromethane (CCl ₃ F), dichlorodifluoromethane (CCl ₂ F ₂ ), chlorotrifluoromethane (CClF ₃ ), tetrafluoromethane Chlorofluorocarbons such as tetrafluoroethylene (CClF ₂ -CClF ₂ ), such as tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl n- Propylsilane (trimethyl-n-propylsilane) and other tetraalkylsilane group.

The aforementioned foaming agent may vary depending on the ratio of cells to be applied. Specifically, based on 100 parts by weight of the prepolymer, the content of the foaming agent may be 0.5 to 40 parts by weight, 1 to 35 parts by weight, or 5 to 30 parts by weight.

The mixed raw material may further include a foam stabilizer as needed. Foam stabilizers improve miscibility by reducing the surface tension of the mixed raw materials, which helps to make the size of the bubbles that can be generated during the mixing process relatively uniform. Foam stabilizers may be, for example, surfactants. The content of the foam stabilizer may be 0.1 to 5 parts by weight based on 100 parts by weight of the prepolymer.

The raw material mixing tool 13 includes: a rotating body 131 rotatably connected to the rotating tool 12 ; and at least one raw material mixing member 132 located in the raw material mixing space 111 rotatably connected to the rotating body 131 .

The rotary tool 12 and the rotary body 131 may be disposed in the raw material mixing space 111 . The rotating tool 12 and the rotating body 131 may be disposed outside the raw material mixing space 111 .

The above-mentioned rotary tool 12 may be installed above the raw material mixing container 11 .

The above-mentioned rotating body 131 may be disposed above the raw material mixing container 11 .

The plurality of rotary tools 12 includes a first drive member 121 and a second drive member 122 .

The first driving member 121 may be connected to the rotation body 131 to rotate the rotation body 131 .

One or two or more second driving members 122 may be disposed on the rotating body 131 .

The first drive member 121 may rotate at a different rate and/or in a different direction than the second drive member 122 to control the rotational movement of the raw material mixing member. Thereby, turbulence can be generated in the mixed raw material located in the raw material mixing space 111, and the homogenization of the mixed raw material can be caused more effectively.

The first driving member 121 may be connected to the rotating body 131 . The first driving member 121 may rotate the rotation body 131 .

The second driving member 122 may be connected to the rotating body 131 . The second driving member 122 may be provided at the rotating body 131 . Two or more second driving members 122 may be disposed on the rotating body 131 , or two or nine second driving members 122 may be disposed on the rotating body 131 . Two or more raw material mixing members 132 may be respectively disposed so as not to interfere with each other.

The raw material mixing member 132 is connected to the second driving member 122 , and can be rotated by the second driving member 122 (second rotation, autorotation) while being rotated by the rotating body 131 (first rotation, revolution). The rotation directions of the above-mentioned first rotation (revolution) and the above-mentioned second rotation (autorotation) may be reversed.

The plurality of rotating tools 12 include: a first driving member 121 connected to the rotating body 131 to rotate the rotating body 131 ; at least one second driving member 122 disposed on the rotating body 131 .

At least one second driving member 122 may be disposed in the rotating body 131 in a manner of being spaced apart from the first driving member 121 . For example, at least one second driving member 122 may be disposed at an edge of the rotating body 131 .

At least one second driving member 122 may be arranged along a circumferential direction of the rotating body 131 with the first driving member 121 as a reference. Although two second driving members 122 are shown in the drawings, the number of second driving members 122 may vary depending on the design of a resin composition mixing device used to prepare a polishing pad.

The first driving member 121 and the second driving member 122 include known motors, and the rotational speeds of the first driving member 121 and the second driving member 122 may be the same or different.

The rotational speed of the first driving member 121 may be 50 rpm to 3000 rpm. The rotational speed of the first driving member 121 may be 80 rpm to 2000 rpm. The rotational speed of the first driving member 121 may be 80 rpm to 500 rpm.

The rotational speed of the second driving member 122 may be 50 rpm to 3000 rpm. The rotational speed of the second driving member 122 may be 80 rpm to 2500 rpm. The rotational speed of the second driving member 122 may be 80 rpm to 2200 rpm.

The ratio of the rotational speed of the first driving member 121 to the rotational speed of the second driving member 122 may be 1:0.1 to 1:40. The ratio of the rotation speed of the first driving member 121 to the rotation speed of the second driving member 122 may be 1:0.8 to 1:30. The ratio of the rotational speed of the first driving member 121 to the rotational speed of the second driving member 122 may be 1:8 to 1:28. The ratio of the rotation speed of the first driving member 121 to the rotation speed of the second driving member 122 may be 1:15 to 1:25. When the mixed raw material is prepared by controlling the rotation speed within the above-mentioned range and rotating the first driving member 121 and the second driving member 122, it is possible to prepare a substantially homogeneous mixed raw material and a reduced aggregate of the solid blowing agent. Mix the ingredients.

The viscosity of the mixed raw material measured at 70° C. may be above 1000 cps, may be 1000 cps to 2300 cps, or may be 1000 cps to 2000 cps. The raw material mixing section can disperse and homogenize the mixed raw material having the above-mentioned viscosity range at a considerable level.

The rotating body 131 is driven by the first driving member 121 to rotate above the raw material mixing container 11 based on the driving shaft (not shown) of the first driving member 121 . In addition, the rotating body 131 may be lifted and lowered by a lifting unit such as an actuator or an electric cylinder. The second driving member 122 may move in a circumferential direction with the first driving member 121 as a reference by the rotating rotating body 131 .

At least one raw material mixing member 132 is connected with at least one second driving member 122 . Accordingly, at least one raw material mixing member 132 moves along the rotating body 131 while being rotated by at least one second driving member 122 . The number of raw material mixing members 132 may be the same as the number of second driving members 122 .

The raw material mixing member 132 includes: a shaft 132a, located in the raw material mixing space 111, and rotatable by being connected with the drive shaft (not shown) of the second drive member 122; and a stirring blade 132b, connected with the shaft 132a, so that The prepolymer and blowing agent accommodated in the raw material mixing space 111 are mixed. The raw material mixing member 132 may be rotated by the second driver 122 and moved by the rotating body 131 to mix the prepolymer and foaming agent in the raw material mixing space 111 . The raw material mixing member 132 is rotatable by the second driver 122 and moved along the circumferential direction of the raw material mixing container 11 by the rotating body 131 to mix the prepolymer and the foaming agent in the raw material mixing space 111 .

The raw material mixing member 132 has stirring blades. The form of the stirring blade can be a paddle type, a turbine type, a propeller type, an anchor type or a helical type stirring blade. When the helical stirring blade is used as the stirring blade, it is beneficial to improve the mixing efficiency.

The raw material mixing unit can efficiently prepare substantially homogeneous mixed raw materials by using two or more driving means and two or more raw material mixing means.

In the raw material mixing section, the raw material mixing tool operated by a plurality of rotating tools effectively mixes and homogenizes the mixed raw material inside the raw material mixing container while rotating, so that the agglomeration phenomenon of a solid blowing agent in the form of a conventional solid powder can be prepared A mixed raw material that is less and the blowing agent is relatively evenly dispersed in the liquid prepolymer.

Raw material mixing section: straight-through (inline) type

A resin composition mixing device for preparing a polishing pad according to another embodiment will be described with reference to FIGS. 6 and 7 .

6 is a schematic diagram illustrating a resin composition mixing device for preparing a polishing pad according to an embodiment, and FIG. 7 is a schematic diagram illustrating a homogenization part in FIG. 6 .

Referring to FIGS. 6 and 7 , the resin composition mixing device 2 for preparing a polishing pad according to an embodiment includes a raw material mixing part 10 , a homogenization part 60 , a filter unit 20 and a pad composition forming part 50 .

The raw material mixing part 10, the filtering unit 20, and the pad composition forming part 50 according to the embodiment are the same as the raw material mixing part, filtering unit, and pad composition forming part according to the embodiment of FIGS.

The homogenization part 60 is located between the raw material mixing part 10 and the filtration unit 20, and the degree of dispersion of the mixed raw material including aggregates is increased to be higher than that of the mixed raw material before passing through the homogenizing part, and is substantially homogenized. The above-mentioned aggregates are formed by coagulating the solid components in at least a part thereof during the process of mixing the solid foaming agent contained in the mixed raw material and the liquid prepolymer.

The homogenization unit 60 may include: a homogenization housing 61 having an inlet 611 and a discharge port 612; a rotor 62 rotatably disposed inside the homogenization housing 61; and a motor 63 connected to the homogenization housing 61 and rotating the rotor 62 .

The rotor 62 can flow the mixed raw material that has flowed into the homogenization housing 61 through the inflow port 611 while being rotated by the motor 63 inside the homogenization housing 61 , and pulverize agglomerates.

Many of the features described in the embodiments shown in Figures 1 to 5 are applicable to this embodiment.

Raw material mixing part: polymix type

A resin composition mixing device for preparing a polishing pad according to still another embodiment will be described with reference to FIGS. 8 and 9 .

FIG. 8 is a schematic diagram illustrating a resin composition mixing device for preparing a polishing pad according to an embodiment, and FIG. 9 is a schematic diagram illustrating a homogenization part in FIG. 8 .

A resin composition mixing device for preparing a polishing pad according to an embodiment has most components of the embodiments described with reference to FIGS. 1 to 5 or 6 to 7 . However, the homogenization part 70 of the embodiment has a different structure from that of the embodiment according to FIGS. 6 and 7 .

Referring to Fig. 8 and Fig. 9, the homogenization section 70 of the resin composition mixing device 3 for preparing a polishing pad according to an embodiment includes: a homogenization housing 71 with an inflow port 711 and a discharge port 712; a shaft (not shown in the figure out), which is power-connected with a motor (not shown in the figure), and is rotatably arranged inside the homogenization shell 71; A plurality of flow holes 731 are formed at intervals along the circumferential direction of the homogenizing plate 73 .

Adjacent homogenization plates 73 may be arranged such that the flow holes 731 are positioned staggered from each other. The homogenization plate 73 may be inclined at a predetermined angle with respect to the shaft to push the mixed raw material flowing into the homogenization housing 71 through the inflow port 711 toward the discharge port 712 .

The mixed raw material flowing in through the inflow port 711 may be homogenized in a manner similar to pulverization while passing through the flow holes 731 of the rotating homogenizing plate 73 . That is, aggregates in the mixed raw material flowing through the homogenization housing 71 are pulverized by the rotating homogenizing plate 73 to be dispersed in the mixed raw material and substantially homogenized.

Many of the features described in the embodiment shown in Figures 1 to 7 are applicable to this embodiment.

filter unit

The filtering unit 20 may be provided in a moving path of the mixed raw material discharged from the raw material mixing container 11 . The filter unit 20 includes a second filter part 22 for separating metal substances from the mixed raw material. The filtering unit 20 may include: a first filter part 21 to filter the mixed raw material according to size; and a second filter part 22 to separate metal substances from the mixed raw material passing through the first filter part 21 .

The mixed raw materials include prepolymer and foaming agent, and solid foaming agent is suitable as the foaming agent. The solid foaming agent in powder form can be mixed with the liquid prepolymer in the mixed raw material, and the powder coagulation and the like may partially occur during the mixing process. The first filter unit 21 can classify and remove the foaming agent and other solid foreign matter existing in the solid state in the liquid mixed raw material by size.

The first filter part 21 includes: a filter case 211 for moving the mixed raw material discharged from the raw material mixing container 11; Mixed raw materials whose size is less than or equal to the predetermined size pass through.

A filter member 212 is provided inside the filter case 211, and a filter space 211a in which the mixed raw material moves is provided.

The upper and lower lengths of the filter housing 211 may be longer than the left and right lengths. The mixed raw material may move along the direction in which the left and right lengths of the filter housing 211 are located.

The left and right lengths of the filter housing 211 may be longer than the top and bottom lengths. The mixed raw material can move along the direction of the upper and lower lengths of the filter housing 211 .

The filter case 211 may include an inlet 211b into which the mixed raw material flows in, and an outlet 211c through which the mixed raw material passed through the filter member 212 is discharged.

One side of the filter case 211 may be formed with an inlet 211b into which the mixed material flows, and the other side may be formed with an outlet 211c through which the mixed material passed through the filter member 212 is discharged.

The inlet 211b and the outlet 211c may face each other substantially on the same line.

The outlet 211c may be provided below the inlet 211b.

The filter member 212 may include a single or a plurality of mesh members.

The filter member 212 is located inside the filter housing 211, and may be provided at an angle greater than 0 degrees and equal to or less than 90 degrees based on the moving direction of the mixed material from the inlet 211b to the outlet 211c. The filter member 212 is located inside the filter housing 211, and may be provided at an angle greater than 45 degrees and equal to or less than 90 degrees based on the moving direction of the mixed material from the inlet 211b to the outlet 211c.

The outer periphery of the filter member 212 is in contact with the inner periphery of the filter housing 211 . Therefore, the mixed raw material does not pass between the filter member 212 and the inner periphery of the filter housing 211 . The mesh members can be made of metal or fibers.

Each mesh member has a different pore size. The filter member 212 may be a mesh member of 50 mesh to 300 mesh.

The filter member 212 may be formed by sequentially arranging mesh members of different sizes along the moving direction of the mixed raw material. When the filter member 212 includes a plurality of members, the members may be arranged in ascending order of mesh number. At this time, the aggregates formed in the mixed raw material passing through the filter housing 211 are sequentially filtered while passing through the mesh member, so efficient filtration can be performed.

Among the mixed raw materials, the mixed raw materials whose size is equal to or larger than the predetermined size are removed, and only the mixed raw materials whose size is smaller than the predetermined size pass through the first filter part 21 .

The filter member 212 as the first filter part 21 has been described above as a mesh member, but is not limited thereto. Various types of members can be applied as long as they can filter the filter objects aggregated into lumps.

The filter housing 211 may include an open hole in which a detachable cover (not shown) is disposed. In a state where the cover is separated, the filter member 212 may be separated from the filter case 211 through the open hole. Therefore, it is possible to remove the lumpy mixed raw material caught in the filter member 212 .

The second filter part 22 includes: a filter housing 221 for the mixed raw material to pass through; a bracket 222 disposed inside the filter housing 211 to contact the passing mixed raw material; and a magnet 223 disposed inside the bracket 222 to generate magnetic force.

The magnetic force generated by the magnet 223 causes the metal substance encapsulated in the mixed raw material to adhere to the periphery of the bracket 222 and be removed. When the mixed raw material from which the metal substance is removed is made into a polishing pad in a subsequent process, damage to the wafer can be reduced.

A frame 222 is provided inside the filter case 221, and a filter space 221a through which the mixed raw material passes is provided.

The mixed raw material may have passed through the first filter unit 21 .

The mixed raw material may have passed through the raw material mixing section 10 .

The upper and lower lengths of the filter housing 211 may be longer than the left and right lengths. The mixed raw material may move along the direction in which the left and right lengths of the filter housing 211 are located.

The left and right lengths of the filter housing 211 may be longer than the top and bottom lengths. The mixed raw material can move along the direction of the upper and lower lengths of the filter housing 211 .

The filter housing 211 may be formed with an inlet 211b into which the mixed raw material flows in, and an outlet 211c through which the mixed raw material passed through the filter member 212 is discharged.

The lower side of the filter case 221 may be formed with an inlet 221b into which the mixed raw material flows.

The inlet 221b is connected to the inner periphery of the filter case 221 in the wiring direction. In addition, an outlet 221c for discharging the mixed raw material passing through the filter space 221a is formed on the upper side of the filter housing 221 . The mixed raw material discharged to the above-mentioned outlet is a mixed raw material from which metal substances have been substantially removed. When viewing the filter housing 211 from the front, the inlet 221 b and the outlet 221 c may be diagonally opposed to each other across the bracket 222 .

The mixed raw material discharged from the raw material mixing part 10 or the first filter part 21 and flows into the inside of the filter case 221 through the inlet 221b along the connection direction causes turbulent flow while contacting the holder 222, and the whole becomes a swirling flow, and flows to the filter housing 221. The direction of the outlet 221c moves in a spiral shape, and discharges to the outside of the second filter unit 22 .

The bracket 222 is provided inside the filter housing 221 .

The bracket 222 may be disposed inside the filter housing 221 in an up and down direction.

The bracket 222 may be disposed inside the filter case 221 in a left-right direction.

Multiple brackets 222 may be provided. Exemplarily, two or more brackets 222 may be provided, or two to nine brackets 222 may be provided.

The outer perimeter of the holder 222 can be in contact with the moving mixed feedstock to create turbulent flow.

In order to increase the contact force between the mixed raw material and the bracket 222, the direction of the length of the bracket 222 can form a certain angle with the swirling flow direction of the mixed raw material, for example, the above-mentioned angle can be greater than 0 degrees and less than or equal to 90 degrees, or can be about 45 degrees to about 90 degrees, or may be substantially right angles. The inside of the bracket 222 may have a receiving space and be empty.

An open hole may be formed in the filter housing 221 , and the open hole may be opened and closed by a detachable cover 224 .

Bracket 222 may be connected to cover 224 . Accordingly, when the cover 224 is separated, the bracket 222 may be pulled out to the outside of the filter case 221 .

The bracket 222 may be directly disposed on the filter housing 221 .

The installation position of the holder 222 can be variously changed according to the design of the resin composition mixing device used to prepare the polishing pad.

The magnet 223 may be a paramagnet and/or an electromagnet.

The magnets may be Neodymium magnets. The magnet may have a magnetic force of 10000 Gauss to 12000 Gauss. A magnet 223 may be located in each bracket 222 and detachably disposed inside.

The mixed raw material passing through the filter space 221 a may not be in direct contact with the magnet 223 . By providing the magnet 223, a magnetic force may be formed around the holder 222, that is, in the filter space 221a. The metal substance mixed in the mixed raw material swirlingly flowing in the filter space 221 a may be attached to the outer periphery of the bracket 222 by the magnetic force of the magnet 223 . Therefore, metal substances can be separated from the mixed raw material passing through the filter housing 221 . The mixed raw material from which the metal substance is separated is discharged to the outside of the second filter part 22 through the outlet 211c.

After separating the metallic substance, the holder 222 may be separated from the filter housing 221 , and the magnet 223 may be separated from the holder 222 . Due to the separation of the magnet 223 , the magnetic force of the periphery of the holder 222 disappears, and the metal substance attached to the outer periphery of the holder 222 by the magnetic force falls off from the outer periphery of the holder 222 . Therefore, metal substance removal work is easily performed.

A scraper (CORNE, not shown in the figure) may be provided along the outer periphery of the bracket 222 , and the scraper may move along the longitudinal direction of the bracket 222 . Metal substances attached to the bracket 222 can be removed by the movement of the scraper. Movement of the scraper may be allowed in a state where the magnet 223 is separated from the bracket 222 , and movement of the scraper may be allowed in a state where the magnet 223 is provided on the bracket 222 .

Since the second filter part 22 forming a magnetic force is located behind the first filter part 21 , metal substances separated by the mesh member of the first filter part 21 can also be separated by the second filter part 22 . Therefore, if the second filter part 22 forming the magnetic force is located behind the first filter part 21, the efficiency of separation by metal substances can be improved.

However, although it is assumed in the above description that the mixed raw material discharged from the raw material mixing container 11 passes through the first filter part 21 and then passes through the second filter part 22, the second filter part 22 may also be provided in the first filter part 21. Before, the mixed raw material discharged from the raw material mixing container 11 was passed through the second filter part 22 to separate metal substances, and then passed through the first filter part 21 to be filtered according to sizes.

The mixed raw material is physically filtered and/or magnetically filtered while passing through the filter unit, thereby removing the above-mentioned solid matter when the size of the solid matter is larger than a predetermined size, and removing the metal substance, so that the filtered mixed raw material can be prepared, and the above-mentioned solid matter Formed by condensation or incomplete homogenization of foaming agents, etc.

By including filtered mixed raw materials in the curable mixture, it is possible to prepare a relatively uniform curable mixture in which foreign matter is substantially minimized.

On the other hand, the resin composition mixing device for preparing a polishing pad according to the present embodiment may further include a storage part 30 storing a mixed raw material that passes through the filter unit 20 to maintain a size below a predetermined size. , and the metal substances in it are removed at the same time. The storage part 30 may include a storage tank, a container, a tank, etc. capable of preventing inflow of foreign matter and protecting the mixed raw material from external factors.

Mat composition forming part

The pad composition forming part 50 is connected to the above-mentioned filtering unit 20 to prepare a curable mixture including filtered mixed raw materials and a curing agent.

The pad composition forming part 50 includes: a mixing container 51 provided with a composition mixing space 511 ; and a mixing member 52 provided in the composition mixing container 51 .

The composition mixing container 51 may be connected to the filter unit 20 and the curing agent supply part 40 through pipes. The composition mixing container 51 may be connected to the storage part 30 and the curing agent supply part 40 through pipes.

A pump or a blower may be provided in the filter unit 20 , the storage part 30 and the curing agent supply part 40 . The filtered mixture raw material and curing agent may be supplied to the composition mixing space 511 of the composition mixing container 51 by the operation of a pump or a blower. In addition, a discharge port (not shown) through which the mixed curable mixture is discharged is formed in the composition mixing container 51 .

The curing agent may include one or more selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, and aliphatic alcohols.

For example, the curing agent can be selected from 4,4'-methylenebis(2-chloroaniline) (MOCA), diethyltoluenediamine, diaminodiphenylmethane, diamino Diaminodiphenyl sulphone, m-xylylene diamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine ( triethylenenetetramine), polypropylenediamine, polypropylenetriamine, ethyleneglycol, diethyleneglycol, dipropyleneglycol, butanediol, hexanediol ( Hexanediol), glycerine (glycerine), trimethylolpropane (trimethylolpropane) and bis (4-amino-3-chlorophenyl) methane (bis (4-amino-3-chlorophenyl) methane) group consisting of one or more .

Based on 100 parts by weight of the polyurethane prepolymer, the content of the curing agent may be 1 to 40 parts by weight, 10 to 30 parts by weight or 20 to 30 parts by weight.

The curable mixture may also contain reaction rate modifiers, as desired.

The reaction rate regulator can be a reaction accelerator or a reaction retarder.

For example, the above-mentioned reaction rate regulator may include triethylene diamine (triethylene diamine, TEDA), dimethyl ethanol amine (dimethyl ethanol amine, DMEA), tetramethyl butane diamine (tetramethyl butane diamine, TMBDA), 2 -Methyl-triethylene diamine (2-methyl-triethylene diamine), dimethyl cyclohexyl amine (dimethyl cyclohexyl amine, DMCHA), triethyl amine (triethyl amine, TEA), triisopropanol amine (triisopropanol amine, TIPA ), 1,4-diazabicyclo (2,2,2) octane (1,4-diazabicyclo (2,2,2) octane), bis (2-methylaminoethyl) ether (bis (2 -methylaminoethyl) ether), trimethylaminoethylenethanol amine, N,N,N,N,N''-pentamethyldiethylene triamine (N,N,N,N,N''-pentamethyldiethylene triamine), Dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-di Methylaminoethylmorpholine (N,N dimethyl aminoethylmorpholine), N,N-dimethylcyclohexylamine (N,N-dimethylcyclohexyl amine), 2-methyl-2-azaborine (2-methyl- 2-azanorbornane), dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate ), dibutyltin di-2-ethylhexanoate and dibutyltin dimercaptide. Specifically, the reaction rate regulator may be one or more selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine.

Based on 100 parts by weight of the polyurethane prepolymer, the content of the above-mentioned reaction rate modifier may be 0.1 to 2 parts by weight.

The curable mixture may have a weight average molecular weight of 500 g/mol to 3000 g/mol.

The curable mixture is a polyurethane resin, which may have a weight average molecular weight (Mw) of 600 g/mol to 2000 g/mol or 700 g/mol to 1500 g/mol.

The gel time of the curable mixture may be from 30 seconds to 300 seconds, or may be from 70 seconds to 180 seconds. The gel time of the curable mixture may be 90 seconds to 110 seconds. In this case, a more workable curable mixture can be prepared.

Composition mixing member 52 comprises: the motor 521 of composition mixing container 51; Shaft 522, can be positioned at the inside of composition mixing container 51 and be connected with the drive shaft of motor 521; And stirring blade 523, in the inside of composition mixing container 51 It is connected with the shaft 522 and mixes the mixed raw material and curing agent accommodated in the raw material mixing space. The motor 521 may be provided externally, and rotate the shaft 522 with a predetermined rotational force.

The stirring blade 523 is rotated inside the composition mixing container 51 by the shaft 522 for a predetermined time, and mixes the filtered mixed raw material and the curing agent to prepare a curable mixture.

The composition mixing member 52 may be connected with a lifting device (not shown in the figure) of an actuator, an electric cylinder, or the like. The composition mixing member 52 can be raised and lowered in the composition mixing container 51 , and the stirring blade 523 can be detached from the inside of the composition mixing container 51 to the outside.

In the raw material mixing section, the raw material mixing tool operated by a plurality of rotating tools moves integrally in the raw material mixing container to uniformly mix the prepolymer and the blowing agent. Therefore, a substantially homogeneous mixture can be obtained.

As the mixed raw material passes through the filtering unit, a state of keeping solid matter above a predetermined size and removing metal substances is achieved, that is, a filtered mixed raw material is obtained. In the composition mixing container of the pad composition forming part, the filtered mixed raw material and curing agent are mixed by the composition mixing member to prepare a substantially uniform curable mixture, and the curable mixture can form a polishing pad to improve the polishing pad The quality of itself minimizes the occurrence of defects such as scratches on the polished object polished by the polishing pad.

Preparation method of polishing pad

A method of preparing a polishing pad according to another embodiment includes a filtering step, a curable mixing step, and a molding step. The method for preparing the polishing pad may further include a padding step after the shaping step.

The filtering step is a step of preparing a filtered mixed raw material by filtering a mixed raw material including a prepolymer and a blowing agent.

Since the specific description about the prepolymer, foaming agent, and mixed raw material overlaps with the above description, description thereof will be omitted. In addition, the filtration process may be performed by passing the above-mentioned mixed raw material through the above-mentioned filtration unit.

In the above filtering process, the physical filtering process and the magnetic filtering process may be performed simultaneously or separately. The physical filtration process and the magnetic filtration process may be performed in sequence.

The curable mixing step is a step of preparing a curable mixture comprising the above-mentioned filtered mixed raw material and a curing agent.

Since specific descriptions about the curing agent and other additives are repeated with the above description, detailed descriptions will be omitted.

The mixing process of the curable mixture may be performed using the mat composition forming part explained above. In this case, the curable mixture can be mixed more efficiently.

The molding step is a step of putting the above curable mixture into a mold and preparing a molded body.

The above-mentioned mold (not shown in the figure) may include a mold capable of forming a molded body with a certain thickness and shape, and the molded body formed by the mold can be used as a polishing layer alone, or as a polishing layer after additional shape processing .

During the molding step, an inert gas may be added. A non-reactive gas can be added during the reaction of the curable mixture to form pores in the shaped body.

The type of inert gas is not particularly limited as long as it does not participate in the reaction between the prepolymer and the curing agent. For example, the inert gas may be one or more selected from the group consisting of nitrogen (N ₂ ), argon (Ar), and helium (He).

The non-reactive gas may be added in an amount of 20% to 35% by volume based on the total volume of the curable mixture. The inert gas may be added in an amount of 20% to 30% by volume based on the total volume of the curable mixture.

After the above molding step, a packaging step may also be included.

The packaging step is a step of packaging the molded body. Before chemical mechanical polishing, the above-mentioned shaped body or polishing layer can be packaged in unit quantities by automatic means and stored or transported.

The padding step is a step of preparing a polishing pad including at least a part of the above-mentioned molded body as a polishing layer.

The polishing pad includes a polishing layer as a top pad.

The average pore size of the polishing layer may be 10um to 30um. When the polishing layer having the above-mentioned average pore size is used, it is beneficial to improve the polishing efficiency of the polishing pad.

The polishing layer may be polyurethane in the form of a foam having an area ratio of 36% to 44%.

The polishing layer may be polyurethane in the form of a foam having 350 to 500 cells per unit area (0.3 cm ² ).

Effective wafer polishing is possible when a polyurethane polishing layer in the form of a foam with these properties is used as a top pad.

As the polishing layer, a polishing layer having a Shore D hardness of 50 to 65 can be used, and in this case, the polishing efficiency can be improved.

As the polishing layer, a polishing layer having a tensile strength of 15N/mm ² to 35N/mm ² can be applied, and in this case, the polishing efficiency can be further improved.

As the polishing layer, a polishing layer having an elongation of 110% to 230% can be used, and in this case, the polishing efficiency can be further improved.

As the polishing layer, a polishing layer having a thickness of 1.5 mm to 3 mm can be used, and in this case, polishing efficiency can be improved.

The polishing layer in the form of a foam includes a plurality of pores, which may have an average size of about 30 um or less, and may range from about 15 um to about 25 um.

An object to be polished that is polished by a polishing layer in the form of a foam has low-defect characteristics, that is, has 3 or less defects and 1 or less scratches based on the entire polished surface of the object to be polished.

The polishing pad may also include a subpad located below the top pad.

The subpad can be of suede type or non-woven type.

The subpad may have an Asker C hardness of 60 to 90.

The thickness of the subpad may be 0.5 mm to 1 mm.

A bonding layer may be provided between the top pad (polish layer) and the subpad.

The top pad (polish layer) and subpad can be attached by a hot melt adhesive layer.

A rubber-based adhesive can be applied to the other side of the subpad.

The other side of the rubber adhesive may be provided with a thin film such as a PET film. The film may also be provided with other rubber-based adhesive layers.

The other side of the subpad can be adhered to the platform of the polishing device by a rubber-like adhesive.

The polishing pad prepared according to the embodiment can substantially suppress the coagulation phenomenon of the solid foaming agent by increasing the dispersion degree of the prepolymer and the foaming agent, and can improve the stability of polishing pad preparation. In addition, when polishing is performed using a polishing pad, storage stability and microfluidity of slurry particles can be easily ensured, so higher-quality polishing can be achieved.

Fractional Purification of Solid Foaming Agent

The solid foaming agent may be fractionally purified by its fractional purification method.

Fractional purification can be carried out by a fractional purification method comprising a solid foaming agent in a fractionation step and a filtration step.

The classification step is a step of dividing the solid foam into first microspheres and second microspheres according to the descending speed which is raised by the flowing gas supplied in the classifying space.

The flowing gas may be dry air or nitrogen, and the moisture content of the first microspheres may be 3% by weight or less.

The filtering step is a step of preparing a fractionated and purified solid blowing agent which is separated and purified from metal substances by a magnetic filter while passing through the filter section through the first microspheres.

When the first microspheres whose moisture content is controlled through the classification step and are classified to have a size and/or weight within a certain range are used as the above-mentioned solid foaming agent, the size and distribution of pores of the polishing layer can be more smoothly controlled, and Metallic foreign matter is also removed by the magnetic filter, so the polishing quality can be further improved.

The solid foaming agent classification and purification device includes: a classification part, which is used to classify the supplied solid foaming agent into first microspheres and second microspheres; a storage part, connected to the above-mentioned classification part, for the classified first microspheres spheres flow in, store and discharge; and a filter part is provided in the moving path of the above-mentioned solid foaming agent or the first microspheres to separate metal substances from the filtering material including the above-mentioned solid foaming agent or the above-mentioned first microspheres.

The above-mentioned filter part may include: a filter housing, inside which is formed a filter space for the above-mentioned solid foaming agent or the above-mentioned first microsphere to pass through; a filter cover, which is detachably arranged on the above-mentioned filter housing to open or close The filter space; and a filter member disposed in the filter space and generating magnetic force.

The above-mentioned metal substance is attached to the above-mentioned filter member by the above-mentioned magnetic force.

The above-mentioned filter member may include: a holder located in the above-mentioned filtering space; and a magnet provided on the above-mentioned holder.

The metal substance can be attached to the bracket to be removed from the filter element.

In the filter housing, a filter inlet connected to the filter space is formed, and the filter inlet may be connected to the periphery of the filter space at the lower portion of the filter housing in a wiring direction.

In the filter space, the filter material may move while being in contact with the filter member while generating a vortex.

A filter discharge port may be formed on the filter housing or the filter cover, and the filter discharge port is connected to the filter space for discharging the filter objects from which metal substances have been removed.

The said filter cover may be provided in the open side of the said filter case, and the said filter discharge port may be formed in the said filter cover.

The filter material may gradually rise while being in contact with the filter member in the filter space, and may be discharged to the outside of the filter case through the filter outlet.

The aforementioned solid foaming agent may have a density of 100 kg/m ³ or less.

Hereinafter, specific examples will be described in more detail. The following examples are merely examples to help understanding of the present invention, and the scope of the present invention is not limited thereto.

Preparation example

1. Grading of solid blowing agent

The unclassified solid blowing agent (Expancel, average particle size: 5.5um, moisture content: 3.5%, density: 47.2kg/m ³ ) was classified by the method of classification purification.

Sample 1 is a foaming agent that is only classified without applying a magnetic filter, and Samples 2, 3, and 4 are foaming agents collected after classification and purification under nitrogen.

The experiment was performed by installing a magnetic filter (magnetic force: 10000G) between the storage unit at the rear end of the classification unit and the classification unit. Vibration rotation is performed by operating a vibration rotor provided in the device, and vibration is applied at 10 Hz to 100 Hz. Applicability is shown in Table 1 below.

Moisture content was measured by measuring 1 g to 3 g of each sample using HX204 (Mettler Toledo Technology Co., Ltd.), and heating at 120°C for 1 minute and 30 seconds to confirm the increase or decrease in weight .

A sample was placed in a 10 cc cell using AccuPyc 1340 (Micromeritics, USA), and the density was measured after measuring the weight.

Average fineness was measured by dispersing the sample in ethanol solvent by S3500+ (Microtrac, USA).

Table 1 sample 1 sample 2 sample 3 Sample 4 flowing gas Not applicable Nitrogen Nitrogen Nitrogen Whether to apply vibration o o o o Is there a magnetic filter x x o o Moisture content after process (weight%) 3.5 1 1.1 1 Solid blowing agent density (kg/m ³ ) 47.2 45.2 45.2 45.1 physical properties 35.5 31.3 31.5 31 Average fineness (μm) Metal removal rate (mg/Kg) 0 0 98 106

Referring to the above Table 1, it was confirmed that compared with Sample 1, the moisture content of Sample 2, Sample 3, and Sample 4 all decreased after the process, and in terms of average fineness or density, the purified and classified examples had lower values .

As for the metal removal rate, sample 3 and sample 4 had metal removal rates of 98 mg/Kg and 106 mg/Kg for sample 3 and sample 4, respectively, so that it was confirmed that a considerable amount of metal foreign matter could be removed by the magnetic filter.

2. Preparation of polishing layer

Put the polyurethane prepolymer (NCO is 9.1% by weight, and the weight average molecular weight is 1200g/mol) and the solid foaming agent classified above into the raw material mixing part, and at the speed (rpm) shown in the following table 2 ) mixing while rotating the first driving tool and the second driving tool, thereby preparing a mixed raw material.

As a mixed raw material, according to the sample, the mixed raw material is prepared by passing through a 70-mesh (gap size of 250um) mesh filter and a magnetic filter in sequence.

Curing agent (bis(4-amino-3-chlorophenyl)methane), inert gas (N ₂ ), reaction rate regulator (tertiary amine compound), etc. are added to the pad composition forming part and mixed to prepare curable mixture.

As the solid foaming agent, 2 parts by weight of the solid foaming agent shown in Table 2 below was used based on 100 parts by weight of the polyurethane prepolymer. After mixing the aforementioned curable mixture, it was poured into a mold (1000 mm in width, 1000 mm in length, and 3 mm in height) to obtain a molded body. Polishing layers having an average thickness of 2 mm were respectively prepared through a process of grinding the above molded body with a flat grinder and notching using a tip.

Table 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Rotational speed of the first driving tool in the raw material mixing section (rpm) 100 100 100 100 100 100 100 Rotational speed of the second driving tool in the raw material mixing section (rpm) 100 500 1000 2000 100 100 100 RPM ratio (1st drive tool:2nd drive tool) 1:1 1:5 1:10 1:20 1:1 1:1 1:1 Whether the rear end of the raw material mixing part is suitable for mesh filter Be applicable Be applicable Be applicable Be applicable Be applicable Be applicable Be applicable Whether the magnetic filter is suitable for the rear end of the raw material mixing part Be applicable Be applicable Be applicable Be applicable Be applicable Be applicable Be applicable Applicable solid blowing agent Sample 4 Sample 4 Sample 4 Sample 4 sample 1 sample 2 sample 3

The above polishing layers were respectively attached to nonwoven fabric type subpads having a thickness of 1.1 mm and a hardness (Shore C) of 70 to prepare polishing pads. The above-mentioned polishing pad was applied to the following evaluation examples.

Evaluation example

1. Physical property measurement of polishing layer

Hardness: To measure the Shore D hardness, cut the polishing pad into a size of 2cm×2cm (thickness: 2mm), and let it stand for 16 hours at a temperature of 23±2°C and a humidity of 50±5%. After that, the hardness of the polishing pad was measured using a durometer (D-type durometer).

Density: Cut the polishing pad into a rectangular quadrilateral (thickness: 2mm) size of 4cm×8.5cm, and let it stand for 16 hours at a temperature of 23±2°C and a humidity of 50±5%. Use a density meter to measure the density of the polishing pad.

Tensile property: As an experimental sample, 5 parts with a width of 150 mm and a length of 10 mm were taken in the mat, and the tensile strength and elongation were measured using a JIS B 7721 tensile testing machine.

2. Measurement of physical properties of pores

Pore average particle diameter: The polishing pad was cut into the size of a regular quadrilateral (thickness: 2 mm) of 2 cm × 2 cm, and observed at 100 times using a scanning electron microscope (SEM, Japan Electron Optics Laboratory (JEOL)) . The total pore diameter is measured from an image obtained using image analysis software, and the number, size, area ratio, etc. are calculated.

3. Polishing performance measurement

The measurement of polishing rate:

Using CMP polishing equipment, after setting a silicon wafer with a diameter of 300mm formed with a silicon oxide film prepared by TEOS-plasma CVD method, the silicon oxide film of the silicon wafer faces downward and is set on the above-mentioned porous polyurethane polishing pad attached on the platform.

Polish the silicon oxide film by adjusting the polishing load to 4.0 psi and rotating the polishing pad at 150 rpm, adding the calcined silica slurry on the polishing pad at a rate of 250 ml/min, and rotating the platform at 150 rpm for 60 seconds.

After polishing, the silicon wafer was removed from the carrier, mounted on a spin dryer, rinsed with purified water (DIW), and then air dried for 15 seconds. Use an optical interferometric thickness measurement device (manufacturer: Keyence, Japan, model name: SI-F80R) to measure the film thickness change of the dry silicon wafer before and after polishing, and calculate the polishing rate by the following formula (Remove Rate, removal rate).

Polishing rate = polished thickness of silicon wafer (Å) / polishing time (60 seconds)

Defect Measurement: Number of Defects in Silicon Wafers

Polishing was performed in the same manner as the polishing rate measurement method using a CMP polishing apparatus. After polishing, the silicon wafer was transferred to a cleaner and cleaned with 1 wt% HF, 1 wt% H2NO3, and purified water (DIW) for 10 seconds, respectively. Then, it was transferred to a rotary dryer, washed with purified water, and then dried with nitrogen for 15 seconds.

The number of defects after polishing of the dried silicon wafer was measured with a defect measurement device (manufacturer: Tenkor Corporation, model name: XP+). Defects are micro scratches or chatter marks. As a result of evaluating a silicon wafer with a diameter of 300mm, the number of defects below is based ^on an area of 70685.83mm2.

table 3 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Polishing layer physical properties: thickness (mm) 2.01 2.01 2.01 2.01 2.01 2.01 2.01 Polishing layer physical properties: hardness (Shore D) 58.1 57.8 57.6 57.2 58.5 58.3 58.2 Physical properties of polishing layer: Density (g/cm ³ ) 0.8 0.8 0.8 0.8 0.8 0.8 0.8 Physical properties of polishing layer: tensile strength (N/mm ² ) 31.0 30.5 29.8 29.5 32.3 31.2 30.2 Polishing layer physical properties: elongation (%) 120 119 118 117 123 121 120 Pore physical properties: number average diameter (um) 25 25 25 25 25 25 25 Pore physical properties: quantity (piece/0.3cm ³ ) 310 315 320 320 318 319 315 Polishing characteristics: Polishing rate (A/min) 2100 2013 2131 2212 2003 2054 2083 Defect (a) 10 5 4 1 8 7 5 Scratches (pieces) 5 2 1 0 6 4 3

Referring to the results of Tables 2 and 3 above, there are differences in the results of defects or scratches depending on the degree of pretreatment of the solid blowing agent applied. However, in the case of Examples 1 to 4 where the same pretreated solid foaming agent was applied, the ratio of the rotational speeds of the first driving tool and the second driving tool, elongation, pore physical properties, polishing rate Etc makes a big difference. It is considered that in the case of Example 3 and Example 2 with a relatively large rotational speed ratio, the number of pores is relatively large, and substantially uniform mixing is performed, so that the agglomerated blowing agent is not removed by a mesh filter, etc., and smoothness is achieved. Scattered so that a relatively large number of pores is observed. In terms of elongation, on the other hand, there is a slight decrease, which can be considered because mechanical denaturation occurs in a part of the polymer chain due to a relatively strong rotation. In terms of polishing rate, when comparing Example 3 and Example 4 in which the number of surface pores was observed to be substantially the same, Example 4 showed a higher polishing rate and less defects and scratches, thereby showing produce the best results.

The preferred embodiment of the present invention has been described in detail above, but the scope of the present invention is not limited thereto, utilize the basic idea of the present invention defined in the scope of protection of the appended invention to be understood by those of ordinary skill in the technical field of the present invention Various modifications and improvements also belong to the scope of the present invention.

1, 2, 3: Resin composition mixing device for preparing polishing pad 10: Raw material mixing department 10a: The first supply department 10b: The second supply department 11: Raw material mixing container 111: Raw material mixing space 12:Rotary tool 121: the first driving member 122: the second driving member 13: Raw material mixing tool 131:Rotate the main body 132: raw material mixing component 132a, 522: shaft 132b, 523: stirring blade 20: Filter unit 21: The first filter part 211, 221: filter housing 211a, 221a: filter space 211b, 221b: entrance 211c, 221c: exit 212: filter components 22: The second filter part 222: Bracket 223: magnet 224: cover 30: storage department 40: Curing agent supply department 50: pad composition forming part 51: Composition mixing container 511: Composition Mix Space 52: Composition Mixing Components 521: motor 60, 70: Homogenization Department 61, 71: Homogenized shell 611, 711: inflow inlet 612, 712: outlet 62: rotor 73: Homogenization plate 731: flow hole

FIG. 1 is a schematic diagram illustrating a resin composition mixing device for preparing a polishing pad according to an embodiment. FIG. 2 is an enlarged view showing a raw material mixing section in FIG. 1 . FIG. 3 is a schematic diagram illustrating a first filter part in FIG. 1 . FIG. 4 is a schematic diagram illustrating a second filter part in FIG. 1 . FIG. 5 is an exploded view of FIG. 4 . FIG. 6 is a schematic diagram illustrating a resin composition mixing device for preparing a polishing pad according to another embodiment. FIG. 7 is a schematic diagram illustrating a homogenization section in FIG. 6 . FIG. 8 is a schematic diagram illustrating a resin composition mixing device for preparing a polishing pad according to another embodiment. FIG. 9 is a schematic diagram illustrating a homogenization section in FIG. 8 .

1: Resin composition mixing device for preparing polishing pad

10: Raw material mixing department

10a: The first supply department

10b: The second supply department

11: Raw material mixing container

111: Raw material mixing space

13: Raw material mixing tool

20: Filter unit

21: The first filter part

22: The second filter part

30: storage department

40: Curing agent supply department

50: pad composition forming part

51: Composition mixing container

511: Composition Mix Space

52: Composition Mixing Components

521: motor

522: axis

523: stirring blade

Claims (10)

A resin composition mixing device for preparing a polishing pad, comprising: Raw material mixing section, used to prepare mixed raw materials including prepolymer and blowing agent; a filtering unit, connected to the raw material mixing part, to filter the mixed raw material; and a pad composition forming part connected to the filtering unit to prepare a curable mixture comprising filtered mixed raw materials and a curing agent, Wherein the raw material mixing section includes a plurality of rotating tools having different rotational speeds from each other. The resin composition mixing device for preparing a polishing pad as claimed in claim 1, wherein the filter unit includes: The second filter part is used to separate metal substances from the mixed raw material; or the filter unit includes: a first filter part for filtering the mixed raw material according to size; and The second filter part is used for separating metal substances from the mixed raw material. The resin composition mixing device for preparing a polishing pad as claimed in claim 2, wherein the first filter part comprises: a filter housing for movement of said mixed stock: and a filter member disposed in the filter housing for passage of the mixed raw material, Wherein the filter member allows the mixed raw material below a predetermined size to pass through. The resin composition mixing device for preparing a polishing pad as claimed in claim 2, wherein the second filter part comprises: a filter housing through which the mixed feedstock passes; a bracket disposed in the filter housing in contact with the passing mixed feedstock; and a magnet disposed inside the bracket and generating a magnetic force, Wherein the metal substance is attached to the periphery of the bracket by the magnetic force. The resin composition mixing device for preparing a polishing pad as described in claim 4, wherein a filter space where the bracket is located is provided inside the filter housing, and the outer periphery of the lower side of the filter housing, An inlet for the mixed raw material to flow into the filter space is provided along the wiring direction of the outer periphery, and an outlet for discharging the mixed raw material is arranged on the outer periphery of the upper side of the filter housing , the mixed raw material is a mixed raw material that passes through the filter space and separates the metal substance. The resin composition mixing device for preparing a polishing pad as claimed in claim 5, wherein the inlet and the outlet are diagonally opposed to each other across the bracket. The resin composition mixing device for preparing a polishing pad according to claim 4, wherein the second filter part further includes a cover detachably coupled to the filter housing and connected to the bracket . The resin composition mixing device for preparing a polishing pad as claimed in claim 1, wherein the raw material mixing part includes: a raw material mixing container provided with a raw material mixing space; and a raw material mixing tool disposed in the raw material mixing space and moved by means of the plurality of rotating tools, Wherein the raw material mixing tool is used to mix the prepolymer and the foaming agent accommodated in the raw material mixing space, and disperse the foaming agent in the mixed raw material. The resin composition mixing device for preparing a polishing pad as claimed in claim 8, wherein the plurality of rotating tools include: a first drive member; and at least one second drive member; Said raw material mixing tool comprises: a rotating body, rotatable by being connected to said first drive member, provided with said at least one second drive member; and at least one raw material mixing member rotated by being connected to said at least one second drive member, Wherein the at least one raw material mixing member is rotated by the at least one second driving member. A preparation method of a polishing pad, comprising: Filtration step, filtering the mixed raw material comprising prepolymer and foaming agent to prepare filtered mixed raw material; A curable mixing step for preparing a curable mixture comprising the filtered mixed raw material and a curing agent; and a molding step of placing said curable mixture into a mold and preparing a molded body, Wherein, through the preparation method of the polishing pad, a polishing pad using at least a part of the molded body as a polishing layer can be prepared, Wherein the filtering step comprises a filtering process using a magnetic filter.

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